Search for Signatures of Extra Dimensions in the Diphoton Mass Spectrum with the CMS Detector

• Main Author: Ma, Yousi
• Format: Others
• Published: 2012
• Online Access: https://thesis.library.caltech.edu/7046/1/thesis_Yousi_Ma_2012.pdf; Ma, Yousi (2012) Search for Signatures of Extra Dimensions in the Diphoton Mass Spectrum with the CMS Detector. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/X33W-ZX56. https://resolver.caltech.edu/CaltechTHESIS:05182012-101542629 <https://resolver.caltech.edu/CaltechTHESIS:05182012-101542629>

A search for signatures of extra dimensions in the diphoton invariant-mass spectrum has been performed with the Compact Muon Solenoid detector at the Large Hadron Collider. No excess of events above the standard model expectation is observed using a data sample collected in proton-proton collisions at √s = 7 TeV corresponding to an intergrated luminosity of 2.2 fb⁻¹. In the context of the Randall–Sundrum model, lower limits are set on the mass of the first graviton excitation in the range of 0.86–1.84 TeV, for values of the associated coupling parameter k ̃between 0.01 and 0.10. Additionally, in the context of the large-extra-dimensions model, lower limits are set on the effective Planck scale in the range of 2.3–3.8 TeV at the 95% confidence level. These are the most restrictive bounds to date.